Laundry Drum Speed Control for Load-Dependent Washing and Drying
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Solution Overview
Problem
Existing laundry machines fail to provide optimal mechanical action during washing and uniform air permeation during drying, as they do not effectively adjust rotational speeds based on laundry load distribution, leading to inefficient washing and drying processes.
Innovation Solution
A method of controlling the rotational speed of the drum in laundry machines, using a microprocessor control and sensors to set different rotational speeds and intermittent idle periods, adjusting the speed range based on load parameters to optimize laundry movement and agitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drum is rotated at a constant high rotational speed to provide strong mechanical action, then washing efficiency is improved, but laundry closer to the axis undergoes rolling movement instead of dropping movement, reducing washing effectiveness
Solution Approach 1:
The patent applies dynamics by varying the rotational speed of the drum during different phases of the washing cycle. The control device adjusts the rotational speed between a first value (higher) and a second value (lower) to optimize laundry movement. This dynamic adjustment ensures that laundry pieces at different distances from the axis experience appropriate forces for effective washing, converting the constant speed operation into a variable speed operation that adapts to the laundry load distribution.
Solution Approach 2:
The patent implements periodic action through alternating rotation cycles with idle periods. The drum rotates at a first rotational speed during a first cycle, then operates at a second rotational speed during a second cycle, with idle periods in between. This periodic variation in rotational speed creates optimal conditions for laundry to be lifted and dropped repeatedly, enhancing mechanical action and washing efficiency while preventing continuous high-speed rotation that would cause rolling instead of dropping movement.
2Productivity
If the drum rotational speed is increased to improve mechanical action, then washing performance is enhanced, but centrifugal force increases preventing laundry from dropping freely
Solution Approach 1:
The control device dynamically adjusts the rotational speed between a first value and a second value during different cycles. By reducing the rotational speed during certain phases, the centrifugal force is decreased, allowing laundry to drop freely under gravity rather than being pinned against the drum wall. This dynamic speed adjustment balances the centrifugal force to optimize the dropping motion essential for effective washing.
Solution Approach 2:
The patent uses periodic alternation between higher and lower rotational speeds. During high-speed cycles, strong mechanical action is provided; during low-speed cycles, centrifugal force is reduced to allow free dropping of laundry. This periodic modulation of rotational speed manages the centrifugal force effect, ensuring that laundry experiences both lifting (at high speed) and dropping (at low speed) phases, which is crucial for effective washing mechanical action.
3Duration of action of moving object
If fixed rotational speed cycles are used to ensure sufficient soaking, then laundry absorption is improved, but mechanical action on laundry is reduced
Solution Approach 1:
The patent implements periodic alternation between rotation cycles at different speeds with idle periods in between. The idle periods provide extended soaking time for the laundry, while the rotation cycles at varying speeds provide mechanical action. This periodic structure combines both soaking and mechanical action phases, ensuring that laundry receives adequate moisture absorption during idle periods and effective washing during rotation phases, thus resolving the contradiction between soaking duration and mechanical action efficiency.
Solution Approach 2:
The control device dynamically varies the rotational speed between first and second values during different cycles, rather than maintaining a fixed speed. This dynamic adjustment allows optimization of both soaking and mechanical action: lower speeds or idle periods enhance soaking, while higher speeds improve mechanical action. The system adapts the rotational characteristics to meet both requirements sequentially, achieving both prolonged soaking and effective mechanical action on the laundry.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method ensures improved mechanical action during washing and uniform air permeation during drying by optimizing rotational speed profiles, enhancing the washing and drying efficiency for various laundry loads.
Implementation Method 1
a measuring device for defining load parameters as a function of the laundry put into the drum
Implementation Method 2
This is brought about by the centrifugal force of the laundry being slightly less than the gravity of the earth
Implementation Method 3
upon release from the wall of the drum, drop down in consequence of gravity
Data Source
AI summary
A laundry treatment method consisting of controlling the rotational speed a program-controlled laundry machine drum between lower and upper limits as a function of at least one predetermined parameter of the laundry within the drum.